Wistar大鼠实验性自身免疫性脑脊髓炎模型性别差异研究

目的:分别建立雌性和雄性Wistar大鼠的实验性自身免疫性脑脊髓炎(EAE)模型,并研究两者的差别。方法:应用非灌注法制备的豚鼠全脊髓匀浆分别免疫雌性和雄性两组Wistar大鼠,诱导建立EAE模型,观察30天,取脊髓组织石蜡包埋,病理切片,HE染色,光镜观察。观察两组大鼠在发病时间、发病率、神经功能评分及病程等方面的区别。结果:雌性Wistar大鼠的平均发病时间(13.67±3.50)天,发病率为60%,病程有复发-缓解的特点,神经功能高峰期评分(2.20±1.96)分;雄性Wistar大鼠的平均发病时间(12.18±1.55)天,发病率为85%,呈一过性发病,神经功能高峰期评分(3.46±1.61)分。结论:雄性Wistar大鼠的EAE模型较雌性Wistar大鼠具有发病率高、单相急性病程等特点,为研究多发性硬化发病机制及其发病的性别差异奠定了一定的基础。     

实验性自身免疫性甲状腺炎动物模型的建立

自身免疫性甲状腺炎是一种常见的器官特异性自身免疫性疾病 ,其病理特征是甲状腺组织内淋巴细胞和单核细胞浸润。实验性自身免疫性甲状腺炎 (EAT)动物模型是研究自身免疫性甲状腺炎的重要工具。目前已经建立的EAT模型可分为自发产生的EAT ,运用T细胞减除法产生的EAT ,以及免疫方法诱导产生的EAT等几类。     

眼前房内抗原注射抑制EAU的发生

目的：探讨眼前房内注射牛视网膜可溶性抗原(S抗原)在诱导眼免疫耐受中的作用。方法：自新鲜牛眼球中提取S抗原，注入Wistar大鼠眼前房内。1周后，皮内注射牛S抗原与弗氏完全佐剂乳化混合物。观察大鼠实验性自身免疫性葡萄膜视网膜炎(EAU)发作时间、临床表现及组织病理学改变；并以ELISA方法检测脾细胞培养上清液中的细胞因子。结果：前房预处理组(groupA)EAU的发生率明显低于阳性对照组(groupB)，所有具有阳性体征者均有组织病理学改变。前房预处理组动物脾细胞培养上清液中的IL-4浓度明显高于阳性对照组；而IFN-γ水平明显低于阳性对照组。结论：前房内注射牛S抗原可以诱导大鼠眼免疫耐受，在很大程度上抑制EAU的发生和发展。     

068 实验性自身免疫性甲状腺炎动物模型的建立

自身免疫性甲状腺炎是一种常见的器官特异性自身免疫性疾病,其病理特征是甲状腺组织内淋巴细胞和单核细胞浸润.实验性自身免疫性甲状腺炎(EAT)动物模型是研究自身免疫性甲状腺炎的重要工具.目前已经建立的EAT模型可分为自发产生的EAT,运用T细胞减除法产生的EAT,以及免疫方法诱导产生的EAT等几类.     

IL-17参与EAU发病及其作用探讨

目的 诱导建立大鼠EAU模型,探讨Th17是否参与EAU发病及其可能的作用机制.方法 用视网膜S抗原与Freund完全佐剂免疫大鼠诱导EAU模型.观察EAU发作时间、EAU临床评分及组织病理学改变,并采用免疫组织化学SP法,检测EAU组和对照组动物眼后部葡萄膜视网膜IL-17的表达.结果 EAU组动物的眼睛在免疫后不同时间发生不同程度的炎症(发病率为100%),临床评分为(3.14±0.61),具有阳性体征者均有葡萄膜视网膜组织病理学改变,模型建立成功.经免疫组织化学染色发现,EAU组IL-17表达阳性率为86%.结论 Th17在EAU的发病机制中可能发挥一定作用.     

在实验性自身免疫性脑脊髓炎模型中探讨MS？…

多发性硬化是一种较常见的中枢神经系统脱髓鞘疾病，Ｔ细胞介导免疫在其发病机制中起一定作用。该病的免疫耐受治疗是目前的研究热点之一，本文综述了近几年在其动物模型实验性自身免疫性脑脊髓炎中进行的研究工作的某些方法和进展。     

IL-12和IL-18在实验性自身免疫性神经炎中的协同作用机制

目的:研究IL-12和IL-18分别在实验性自身免疫性神经炎(EAN)中的调节机制以及IL-12与IL-18的协同作用.方法:建立P0180-199特异性T细胞系.分别用IL-12或IL-18或者IL-12和IL-18进行体外干预,将不同处理组的T细胞回输到正常的大鼠体内,建立过继免疫的EAN动物模型.应用国际分级标准和临床评分对发病鼠进行临床评定;通过免疫组化检测不同组EAN鼠坐骨神经淋巴细胞浸润;ELISA法检测相关细胞因子的变化.结果:①在IL-12和IL-18共同干预的条件下,特异性T细胞TNF-α和IFN-γ的产生均增加;②与IL-12或IL-18组相比,IL-12 IL-18组大鼠临床发病明显加重,发病时间提前;③在坐骨神经标本中,与对照组相比,IL-12 IL-18组CD4 淋巴细胞浸润数量较多,而IL-12和IL-18组CD4 淋巴细胞浸润较少.结论:经IL-12和IL-18体外干预的P0180-199特异性T淋巴细胞,通过过继免疫给正常大鼠后,诱导出严重的EAN动物模型,表现出协同增强作用.     

胸腺五肽治疗实验性自身免疫性脑脊髓炎的实验研究

目的 应用胸腺五肽(thymopentin,TP-5)干预实验性自身免疫性脑脊髓炎(experiment autoimmue encephalomyelitis,EAE)大鼠,探讨该药物对EAE的治疗作用及其机制.方法 以豚鼠全脊髓匀浆(guinea pig spinal cord homogenate,GPSCH)与完全弗氏佐剂(CFA)为抗原免疫Wistar大鼠建立EAE模型.Wistar大鼠随机分为正常对照组、EAE组、地塞米松(dexamethasone,DXM)组、TP-5小剂量组、TP-5大剂量组.采用双抗体夹心ELISA法检测Wistar大鼠免疫后7、14、21 d不同时间点血清中IL-12、IL-10的含量.结果 与EAE组和TP-5大剂量组比较,TP-5小剂量组和DXM组大鼠的发病率和临床评分显著性降低(P＜0.01);DXM组大鼠的发病率和临床评分低于TP-5小剂量组(P＜0.01).各个时间点EAE组、DXM组、TP-5小剂量组、TP-5大剂量组IL-12含量均较正常对照组明显升高(P＜0.01),免疫后14、21 d DXM组和TP-5小剂量组IL-12水平比EAE组低(P＜0.01);免疫后14、21 dDXM组、TP-5小剂量组IL-10水平与其余3组比较明显升高(P＜0.01).结论 TP-5对EAE有保护作用,其作用机制可能与上调IL-10水平以及下调IL-12水平有关,通过双向调节作用逆转TH1/TH2失衡.     

连翘提取物对实验性自身免疫性甲状腺炎大鼠甲状腺损伤的影响

目的：探讨连翘提取物（FSE）对实验性自身免疫性甲状腺炎（EAT）的影响及其可能的作用机制。方法：将90只SD大鼠分为对照组、模型组、FSE 25 mg/kg组、FSE 50 mg/kg组、FSE 100 mg/kg组和硒酵母片组（Selenious组,300μg/kg）,除对照组外,其余各组大鼠均采取皮下注射含猪甲状腺球蛋白的不完全弗氏佐剂制备EAT模型,末次注射完成后FSE25 mg/kg组、FSE 50 mg/kg组、FSE 100 mg/kg组分别给予25、50、100 mg/kg FSE灌胃,Selenious组灌胃300μg/kg硒酵母片,模型组和对照组灌胃等体积生理盐水,连续灌胃2周。HE染色观察甲状腺病理学变化,放射免疫法测定甲状腺功能血清学指标,qRT-PCR检测甲状腺组织炎症相关因子的mRNA水平,ELISA检测血清氧化应激指标,Western blot检测NLRP3/Caspase-1通路蛋白表达情况。结果：对照组甲状腺泡呈椭圆形或圆形,甲状腺组织无淋巴浸润现象,模型组甲状腺泡萎缩、损伤,且伴有上皮增生和间质淋巴浸润现象,FSE(50、100 mg/kg)组、Se...     

细胞因子在实验性自身免疫性脑脊髓炎耐受中的作用

细胞因子(CK)在实验性自身免疫性脑脊髓炎(EAE)的免疫机制中起着重要作用。Th细胞的不同转化决定EAE的发生、发展或抑制。由多种CK构成的免疫调节网络操纵着Th细胞的免疫应答。通过作用Th细胞使之向抑制EAE方向转化,从而寻找对EAE耐受的途径,是目前EAE研究的一个重要方面。以下就与EAE耐受相关的CK研究进行综述,探讨EAE免疫病理机制。     

The role of the ICOS/B7RP-1 T cell costimulatory pathway in murine experimental autoimmune uveoretinitis

ICOS/B7RP-1 is a new member of the CD28/B7 family of costimulatory molecules and plays differential roles in autoimmune diseases. In this study, we examined the role of ICOS/B7RP-1 pathway in the pathogenesis of mouse experimental autoimmune uveoretinitis (EAU), an animal model of human autoimmune uveitis. ICOS expression was found on infiltrating CD4+ T cells in the region of the retina in EAU-induced mice. The anti-B7RP-1 monoclonal antibody (mAb)-treated or ICOS-deficient mice showed a substantial reduction of disease scores. Blockade of ICOS/B7RP-1 interaction during the effector phase ameliorated the disease, whereas its blockade during the induction phase exhibited no significant effect. Moreover, administration of anti-B7RP-1 mAb effectively ameliorated the disease induced by adoptive transfer of pathogenic T cells. The anti-B7RP-1 mAb treatment inhibited the expansion and/or effector function of pathogenic T cells, given that proliferative response and IFN-gamma production by lymph node cells were reduced upon restimulation with the antigen peptide in vitro. These results suggest that the ICOS/B7RP-1 interaction plays a critical role in the pathogenesis of uveitis. We also indicated that ICOS-mediated costimulation plays differential roles in EAU and experimental autoimmune encephalomyelitis, which is also a Th1 disease induced in the same manner as EAU.     

Identification of genomic regions controlling experimental autoimmune uveoretinitis in rats

The present study attempts to identify specific genetic locicontributing to experimental autoimmune uveoretinitis (EAU)susceptibility in F₂ progeny of resistant Fischer (F344/N) andsusceptible Lewis (LEW/N) inbred rats. F₂ progeny of F344/Nx LEW/N inbred rats were immunized with the R16 peptide of interphotoreceptorretinoid-binding protein (IRBP). A genome-wide scan was conductedusing 125 simple sequence length polymorphism markers in selectedF₂ animals that developed severe eye disease or remained unaffectedto identify phenotype:genotype co-segregation. The F₂ population(n = 1287) demonstrated a wide range of histologically assessedEAU scores (assessed on a scale of 0–4). The disease incidenceand severity were not consistent with a simple Mendelian inheritancemodel. Of the F₂ hybrid rats, 60% developed EAU, implying theexistence of a potent susceptibility locus with incomplete penetranceassociated with the LEW genome or a more complex polygenic modelof inheritance. Two genomic regions, on chromosomes 4 and 12,showed strong genetic linkage to the EAU phenotype (P < 0.0016),suggesting the presence of susceptibility loci in these chromosomalregions. In conclusion, we have identified two genomic candidateintervals from D4Arb8 to D4Mit17 on chromosome 4 and from thechromosome end to D12Arb8 on chromosome 12, that appear to influenceEAU susceptibility in LEW/F344 rats. Further analysis of thesegenomic regions may lead to identification of the susceptibilitygenes and to characterization of their function.     

Inhibition of the alternative pathway of complement activation reduces inflammation in experimental autoimmune uveoretinitis

We have shown previously that complement factor H (CFH) and complement factor B (CFB) are constitutively expressed by retinal pigment epithelial cells and their production is regulated by inflammatory cytokines, suggesting that the alternative pathway (AP) of complement activation might play a role in retinal inflammation. In this study, we further investigated the role of the AP in retinal inflammation using experimental autoimmune uveoretinitis (EAU) as a model. Mice with EAU show increased levels of C3d deposition and CFB expression in the retina. Retinal inflammation was suppressed clinically and histologically by blocking AP‐mediated complement activation with a complement receptor of the Ig superfamily fusion protein (CRIg‐Fc). In line with reduced inflammation, C3d deposition and CFB expression were markedly decreased by CRIg‐Fc treatment. Treatment with CRIg‐Fc also led to reduced T‐cell proliferation and IFN‐γ, TNF‐α, IL‐17, and IL‐6 cytokine production by T cells, and reduced nitric oxide production in BM‐derived macrophages. Our results suggest that AP‐mediated complement activation contributes significantly to retinal inflammation in EAU. CRIg‐Fc suppressed retinal inflammation in EAU by blocking AP‐mediated complement activation with probable direct effects on C3/C5 activation of macrophages, thus leading to reduced nitric oxide production by infiltrating CRIg^? macrophages.     

Orally induced bystander suppression in experimental autoimmune uveoretinitis occurs only in the periphery and not in the eye

Oral administration of retinal soluble antigen (S-Ag) suppresses the induction of S-Ag-mediated experimental autoimmune uveitis (EAU) in Lewis rats. EAU induced with interphotoreceptor retinoid-binding protein (IRBP), another retinal autoantigen, can also be suppressed by oral administration of IRBP. It has been speculated that feeding with one retinal autoantigen could suppress induction of uveitis with the other retinal protein by means of bystander suppression. Both uveitogenic effector and suppressor cells should find their antigens within the retina, where the suppressor cells would be expected to act on the effector cells. However, reciprocal combinations of antigens used for induction and suppression of uveitis failed to prevent onset of disease, demonstrating that bystander suppression obviously does not occur in the eye. To investigate further the localization of suppressor mechanisms, we fed Lewis rats either with retinal S-Ag or with ovalbumin (OVA) and then immunized the animals either with a mixture of S-Ag and OVA or with each antigen separately, injected into contralateral hind legs. Feeding of S-Ag prior to immunization led to suppression of uveitis, whereas feeding of OVA had no tolerizing effect when S-Ag and OVA were injected into different legs. Nevertheless, immunizing rats with a mixture of S-Ag and OVA after OVA feeding suppressed uveitis to a high degree. These findings suggest that orally induced bystander suppression might not occur in the target organ, but rather peripherally at the site of induction of the autoimmune T cells.     

Intraocular injection of tamoxifen-loaded nanoparticles: a new treatment of experimental autoimmune uveoretinitis

In this study, we tested the efficiency of an intravitreal injection of tamoxifen, a non-steroidal estrogen receptor modulator, in retinal soluble antigen (S-Ag)-induced experimental autoimmune uveoretinitis (EAU). To increase the bioavailability of tamoxifen, we incorporated tamoxifen into polyethylene glycol (PEG)-coated nanoparticles (NP-PEG-TAM). The localization of the nanoparticles within the eye was investigated using fluorescent-labeled PEG-coated nanoparticles after injection into the vitreous cavity of rats with EAU. Some nanoparticles were distributed extracellularly throughout the ocular tissues, others were concentrated in resident ocular cells and in infiltrating macrophages. Whereas the injection of free tamoxifen did not alter the course of EAU, injection of NP-PEG-TAM performed 1-2 days before the expected onset of the disease in controls resulted in significant inhibition of EAU. NP-PEG-TAM injection significantly reduced EAU compared to injection of NP-PEG-TAM with 17beta-estradiol (E2), suggesting that tamoxifen is acting as a partial antagonist to E2. Diminished infiltration by MHC class II(+) inflammatory cells and low expression of TNF-alpha, IL-1beta, and RANTES mRNA were noted in eyes of NP-PEG-TAM-treated rats. Intravitreal injection of NP-PEG-TAM decreased S-Ag lymphocyte proliferation, IFN-gamma production by inguinal lymph node cells, and specific delayed-type hypersensitivity indicative of a reduced Th1-type response. It increased the anti-S-Ag IgG1 isotype indicating an antibody class switch to Th2 response. These data suggest that NP-PEG-TAM inhibition of EAU could result from a form of immune deviation. Tamoxifen-loaded nanoparticles may represent a new option for the treatment of experimental uveitis.     

The matrix metalloproteinase inhibitor BB-1101 prevents experimental autoimmune uveoretinitis (EAU)

EAU is characterized by breakdown of the blood-retinal barrier and extravasation of leucocytes into retinal tissue leading to destruction of photoreceptor cells. Matrix metalloproteinases (MMP) have been implicated in trafficking of cells into tissues, but their role in inflammatory eye disease is unclear. A synthetic MMP inhibitor, BB-1101, was administered subcutaneously, from either day 0 or day 7, to Lewis rats challenged with bovine S-antigen to induce EAU. When given up to day 14, BB-1101 reduced the incidence of disease and delayed the day of onset of clinical disease. When administered from day 7 until day 21, EAU was completely abrogated. A quantitative polymerase chain reaction (PCR) assay showed an increase of both matrilysin (MMP-7), neutrophil collagenase (MMP-8) and macrophage metalloproteinase (MMP-12) in retinas from EAU animals compared with naive controls. These enzymes are produced by activated leucocytes and act on components of the basement membrane. These results therefore implicate these MMP as integral to the development of pathology in EAU.     

TH2 activated cells prevent experimental autoimmune uveoretinitis,a TH1-dependent autoimmune disease

Mercuric chloride (HgCl₂) injections protect (Lewis x Brown-Norway) F1 (F1) rats against experimental autoimmune uveoretinitis (EAU) induced by immunization with the retinal S antigen (S-Ag); in contrast HgCl₂-injected F1 rats develop EAU following transfer of lymph node (LN) cells from rats immunized with S-Ag alone. In the present study we demonstrate that the ability of LN cells from rats protected against EAU to transfer the disease into naive F1 rats was considerably reduced. These LN cells neither produced interleukin (IL)-2 nor (interferon (IFN)-γ but exhibited mRNA for IL-4. In contrast, LN cells from diseased rats easily transferred EAU into naive F1 rats, produced significant IL-2 and IFN-γ levels but barely exhibited mRNA for IL-4. Furthermore protected rats predominantly produced IgG2b anti-S-Ag antibodies, while diseased rats produced IgG2b anti-S-Ag antibodies and the increase in expression of MHC class II molecules on B cells was higher in protected rats than in diseased rats. These data suggest that (1) to exert a protective effect, HgCl₂ must act at an early stage of differentiation of precursors of S-Ag specific T cells, and (2) this effect is related to the preferential activation of TH2 cells to the detriment of uveitogenic TH1 cells. Finally, these results indicate that activation of TH2 cells protect from a TH1-dependent autoimmune disease.     

Effect of sex hormones on experimental autoimmune uveoretinitis (EAU)

Purpose: Sex hormones have been associated with the prevalence, susceptibility, and severity of autoimmune disease. Although the exact mechanism is unknown, sex hormones are reported to influence cytokine production, specifically by affecting the balance of Th1 and Th2 effector cells. We evaluated the effect of estrogen, progesterone, and testosterone in autoimmune uveoretinitis (EAU), a rodent model of human ocular autoimmune disease. Methods: Lewis rats implanted with either β-estradiol (estrogen), 5-dihydrotestosterone (5-DHT), norgestrel (progesterone), or estrogen plus progesterone were immunized with the retinal antigen interphotoreceptor retinoid binding protein (IRBP) peptide. Evaluation of EAU was based on histology of the eyes and measurement of peripheral immunological responses of DTH and lymphocyte proliferation to S-antigen. Quantitative RT-PCR was used to measure IFN-γ and IL-10 mRNA in the eyes. Results: In female rats 5-DHT significantly decreased, estrogen slightly enhanced, but progesterone or estrogen + progesterone did not affect EAU. In contrast, in male rats 5-DHT slightly decreased, estrogen moderately decreased, progesterone did not effect, but, estrogen + progesterone slightly decreased EAU. The results correlated with the ocular levels of Th1 (IFN-γ) and Th2 (IL-10) cytokine messengers. Conclusion: The data support the hypothesis that sex hormones may affect autoimmune diseases by inducing changes in the cytokine balance. This suggests that sex hormone therapy could be considered as an adjunct to anti-inflammatory agents to treat ocular autoimmune diseases in humans.     

Peptide-mediated suppression of experimental autoimmune uveoretinitis in mice: development of a peptide vaccine

Experimental autoimmune uveoretlnltls (EAU) Is an animal modelof antigen-specific, T_h cell-mediated, organ-specific autoimmunedisease. EAU is induced by immunization of B10.A mice with Interphotoreceptorretlnold-binding protein (IRBP). Pre-treatment with syntheticpeptlde 518–529 derived from IRBP prevented IRBP-medlatedEAU. This was accompanied by augmentation of the IRBP-speciflclgG1 antibody (T_h2) response and down-regulation of the IRBP-specfflclgG2a (T_h1) response. Consistent with this is the observationthat two of two T cell lines established from p518–529-primedmice produced T_h2-type cytokines (IL-4 and IL-10), whereas threeof three T cell lines obtained from IRBP-prlmed mice producedT_h1-type cytokines (IL-2 and IFN-). Together this suggests thepossibility that p518–529 priming causes a shift froma T_h1- to a T_h2-domlnated Immune response, thereby playing apivotal role In the prevention of IRBP-mediated EAU. Furthermore,co-transfer of cells from a CD4⁺ p518–529-specfflc T cellline prevented the development of EAU after adoptive transferof spleen cells from mice with EAU Into normal mice. These findingscontribute to our understanding of the mechanism of EAU, particularlywith respect to the down-regulation of T_h1-initiated Inflammation,and may prove valuable for designing a peptlde vaccine for EAUIn the future.     

Human immunoglobulin preparations for intravenous use prevent experimental autoimmune uveoretinitis

We have evaluated the effect of human Igs for intravenous use(IVIg) on the onset and development of experimental autoimmuneuveoretinitis (EAU), a T cell-dependent autoimmune disease inducedin rats by a single immunization with retinal S-antigen (S-Ag).Five consecutive daily infusions of IVIg, starting on the sameday as S-Ag immunization, protected (Lewis x Brown-Norway) F¹rats against EAU. The prevention of EAU was IVIg-specific, i.e.mediated by pooled human IgG from multiple donors, since neitherinfusions of BSA nor infusions of pooled Ig from only two healthyindividuals were effective. Treatment with IVIg decreased lymphocyteprollferative and antibody responses to S-Ag and the proliferativeresponse to concanavalin A. Lack of proliferation was not dependentupon generation of suppressor cells. Lymph node (LN) cells fromIVIg-treated and S-Ag-immunized animals neither proliferatednor secreted IL-2 in response to S-Ag but proliferated whenco-cultured with LN cells from rats immunized with S-Ag. Ourfindings are compatible with an induction of a state of functionalinactivatlon/anergy of T lymphocytes by infusions of IVIg. Thisfunctional inactivation may be due to the presence in IVIg ofantibodies that bind both in vivo and in vitro to rat lymphocytes.Results from the present study suggest a novel mechanism bywhich IVIg may be beneficial in human autoimmune diseases.